The present invention relates to an ejection seat.
As an ejection seat initiates an eject procedure, a rocket motor or other propulsion system causes the seat to be propelled upwardly out of the cockpit. A parachute subsequently deploys and the ejection seat and its occupant return to the ground. As the ejection seat exits the cockpit, it enters into the wind blast passing over the cockpit, which imparts a wind force on the pilot's body. As a result, the user's head and/or limbs can flail around in the windblast, risking injury to the pilot and/or affecting the motion of the seat as it leaves the cockpit.
Moreover, at the point of ejection—generally occurring at a point of emergency—the occupant might not be seated in the ejection seat in the optimal position. For example, the occupant might be leaning forwards in the seat, the occupant's head might be angled with respect to the centre of the seat, and/or the occupant's arms might be outside of the space envelope of the seat. In some situations, the occupant may be unconscious or otherwise incapacitated to some extent. Undesirable positioning of the occupant's body or head is referred to as being “out of position”.
It will be appreciated that if an ejection sequence is initiated when the seat occupant is out of position, the forces imparted by the wind blast may exacerbate the misalignment of the occupant with the seat, risking injury. In cases where the occupant's head is near the edge of the headrest, the windblast force could cause the occupant's head to move behind the plane of the headrest, risking serious injury.
Moreover, as the seat leaves the cockpit, there is a risk that an out-of-position occupant could strike the side of the cockpit or equipment in the cockpit, causing injury or, at the very least, adversely affecting the ejection path from the cockpit.
The applicant has previously proposed a headrest assembly, published as WO2012/013985, the contents of which are incorporated herein in their entirety.
There is a need to ensure that an occupant of an ejection seat is maintained in or near an optimal position throughout the ejection procedure, and/or to minimise the risk of a occupant's limbs from flailing around during ejection.